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Slow job execution with a package: parse numbers =ejecute numbers

Posted on 2013-05-13
Medium Priority
Last Modified: 2013-05-17
Hi folks, I'm experiencing extremely slow in the execution of a package (see attached HISR_FUTURE.pks HISR_FUTURE.pkb)

The same done  inserts or update, in a particular table, for each pointnumber to detect, with data every five minutes, with an age of 180 days.

To perform an insert of only 2 points takes 42 seconds, on a test table without data.

The real problem arises when pointnumbers are many, say 50 pointnumbers and the table has several million records, taking over 20 hours to complete.

Do not throw any errors. The table are not partitioned.

SQL> select * from v$version;

Oracle Database 11g Release - 64bit Production
PL/SQL Release - Production
CORE      Production
TNS for Linux: Version - Production
NLSRTL Version - Production

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Doing a trace of the session running the job, I see that the number of parse is = to the number of execute that takes (see line 2455 file.out file.)

   ( :past_date_found, :device_1 )

call count cpu elapsed disk query current rows
-------------------------------------------------- ---------------------
Parse 228098 2.65 2.69 0 0 0 0
Execute 228098 16.30 17.51 48 234385 1736931 228098
Fetch 0 0.00 0.00 0 0 0 0
-------------------------------------------------- ---------------------
Total 456196 18.95 20.20 48 234385 1736931 228098

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Almost equal to the totals (see line 2727):


call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse   228335      2.67       2.71          0          4          0           0
Execute 228415     16.36      17.79         50     234575    1737155      228129
Fetch      148      0.00       0.02          1        424          0          74
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total   456898     19.04      20.54         51     235003    1737155      228203

Misses in library cache during parse: 19
Misses in library cache during execute: 5

   51  user  SQL statements in session.
  123  internal SQL statements in session.
  174  SQL statements in session.
   12  statements EXPLAINed in this session.

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I replaced the way it looks for the maximum as follows:

- line 511
- 'Select' | | hisr_mngr_rec.datetimecolumnname | | '
from (SELECT * FROM '| | hisr_mngr_rec.tablename | |'
ORDER BY '| | hisr_mngr_rec.datetimecolumnname | |' DESC)
where rownum = 1 '; 

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- line 693
'Select' | | hisr_mngr_rec.datetimecolumnname | | '
from (SELECT * FROM '| | hisr_mngr_rec.tablename | |'
ORDER BY '| | hisr_mngr_rec.datetimecolumnname | |' DESC)
where rownum = 1 and ';

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But I got no changes.

They could give me an idea how to improve this behavior?

As I can speed up the execution of the job?

If you need more information, please apply

Thank you!
Question by:carlino70
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LVL 29

Accepted Solution

MikeOM_DBA earned 1500 total points
ID: 39162903
As a start:
1) Change all these OPEN/FETCH/CLOSE to single sql statements to eliminate a lot of the parsing:
      || check for device number columns
      OPEN checkdevs_cur(hisr_mngr_rec.FrequencyEntryNumber);
      FETCH checkdevs_cur INTO num_sets;
      CLOSE checkdevs_cur;
      -- To this:
      SELECT count(DISTINCT DeviceSetFK)
        FROM HISRDeviceRange 
        INTO num_sets
       WHERE FrequencyEntryFK = hisr_mngr_rec.FrequencyEntryNumber;
      -- Or this (create function):
      num_sets := checkdevs_func(hisr_mngr_rec.FrequencyEntryNumber);

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2) For the queries with MAX() -- lines 511 and 693 -- Create indexes on all tables on those columns:
CREATE INDEX {DateTimeColumnName}_IDX
    ON {TableName}({DateTimeColumnName} DESC)
    . . .  E t c . . .

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Author Comment

ID: 39175199
Mike, I created the indexes on utctime column and the behavior is much better.

Also, I changed the search looking  
rownum = 1 

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Thanks again!

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